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Mixed separator appliance: A new option for maxillary expansion
orthodontic waves 69 (2010) 33–38
available at www.sciencedirect.com
journal homepage: www.elsevier.com/locate/odw
Short communication
Mixed separator appliance: A new option for maxillary expansion Matheus Melo Pithon * Faculty of Dentistry, Federal University of Rio de Janeiro – UFRJ, Brazil
article info
abstract
Article history:
The aim of this article was to describe the fabrication and clinical application of a new
Received 16 September 2009
separator appliance that allies the favorable characteristics of the Haas and Hyrax types of
Received in revised form
separators. With this appliance separation of the median palatine suture was achieved with
4 November 2009
greater support with the acrylic component in the active period and better hygiene without
Accepted 10 November 2009
the acrylic component in the period of containment. Therefore it could be concluded that
Published on line 9 December 2009
the mixed separator appliance is a good option for performing rapid maxillary expansion. # 2009 Elsevier Ltd and the Japanese Orthodontic Society. All rights reserved.
Keywords: Rapid maxillary expansion Maxillary expansion
1.
Introduction
One of the most recognized clinical procedures in orthodontic practice, due to its efficiency and predictability, is rapid maxillary expansion (RME) [1]. RME or separation corrects the transverse atresia of the maxilla, an extremely frequent type of malocclusion that is established early and is not selfcorrecting [2]. The literature mentions an infinite number of appliances used for this purpose [3–9], nevertheless, the most used and disseminated appliances up to today are the appliances of the Haas [10] and Hyrax type [11,12]. The Haas separator appliance idealized by this author in 1961 [10] is composed of orthodontic bands fabricated for the first molar and first premolar on each side, which are united by a structure made of stainless steel wire by the vestibular and palatine ends of the bands, and a central screw. All these elements are incorporated into an acrylic mass that stays in contact with the palatine mucosa. The Haas appliance uses a dento-mucosal supported anchorage system. The magnitude
of force released by this appliance, associated with its anchorage system, provide excellent orthopedic movement (movement of the bone bas) with minimal orthodontic movement response (tooth movement). However, when this appliance is removed, thick biofilm accumulation is noted under the acrylic component. In an endeavor to make the separator more hygienic, Biederman [11,12] developed the Hyrax appliance which, in the same way as the Haas appliance is fabricated with bands on the first molars and first premolars, which are united by the vestibular and palatine faces, by means of a stainless steel wire and an expansion screw that has four cast steel wire rods, and each of these rods is welded to the four bands of the molars and premolars. It is differentiated from the Haas by the anchorage, which in this model anchorage is purely dental. It presents a certain amount of orthodontic movement (tooth movement), in addition to orthopedic movement (bone movement), which would be its limitation [13].
* Correspondence address: At Av. Ota´vio Santos, 395, sala 705, Centro Odontome´dico Dr. Altamirando da Costa Lima, Vito´ria da Conquista, CEP: 45020-750, Bahia, Brazil. Tel.: +55 7730842020. E-mail address: [email protected]. 1344-0241/$ – see front matter # 2009 Elsevier Ltd and the Japanese Orthodontic Society. All rights reserved. doi:10.1016/j.odw.2009.11.001
34
orthodontic waves 69 (2010) 33–38
In an endeavor to reduce the limitations of these two appliances, the aim of the present article was to describe the fabrication of a new separator appliance that allies the favorable characteristics of the Haas and Hyrax types of separators.
2.
Case report
The patient with 13-year-old leukoderma boy, came to the orthodontic consulting rooms with the chief complaint of
crooked teeth. In the intraoral clinical exam, maxillary atresia was noted, with lack of space for eruption of the maxillary left canine (23) (Fig. 1). As complementary exams, periapical, panoramic, teleradiographic and superior occlusal radiographs of the maxilla were requested (Fig. 1f). From the preceding evaluations, the option was to perform orthopedic– orthodontic treatment, beginning with the placement of a maxillary suture separating orthodontic appliance, followed by correcting the position of the teeth by means of a fixed orthodontic appliance.
Fig. 1 – (a–e) Initial intraoral photographs and (f) initial occlusal radiograph.
orthodontic waves 69 (2010) 33–38
35
Fig. 2 – (a) Screw adaptation, (b) welding the screw to the orthodontic bands, (c) isolation of the screw orifices and making the dyke with radiographic film, (d) concluded appliance and (e) intraoral photographs after placement of the separator.
3.
Description of the separator appliance used
The appliance was fabricated on bands adapted to the maxillary first premolars (14 and 24) and maxillary first molars (16 and 26). Once the transfer model with the bands in place was obtained, an expansion screw with long rods was contoured. After contouring, the rods were welded to the bands, and the weld was polished.
After this, the screw was covered with wax to prevent the resin from obliterating the orifices for the purpose of activating it during acrylization. In order to separate the acrylic components of the left and right sides, a piece of used radiographic film served as a dyke, and was placed exactly over the median palatine suture. After the preparatory stage, the acrylic component was applied by the powder/liquid technique. Once it was polymerized, it was finished and polished (Fig. 2).
36
orthodontic waves 69 (2010) 33–38
Fig. 3 – (a–d) Intraoral photographs at the end of 21 of activation and (e) occlusal radiograph after separation.
4.
Activation of the appliance
After cementation (Fig. 2e), a period of 30 min was waited before performing the first activations. Initially it
was activated 4 (1 mm), and the patient was instructed to activate it 2 a day for 7 days, and then return to the consulting room. At the end of 21 days of activation, the necessary separation of 11.5 mm was obtained (Fig. 3).
orthodontic waves 69 (2010) 33–38
37
Fig. 4 – (a) Acrylic surface wear, (b) acrylic displacement with the sharp pointed instrument; (c) acrylic removal with forceps, (d) polishing the metal structure, (e) appliance after removal of the acrylic component and (f) acrylic component removed.
5. Stabilization and removal of the acrylic component After obtaining the desired separation, the screw was stabilized with a braided ligature wire. In the same session, the acrylic component was removed with the aid of a bur for resin removal mounted in a high speed handpiece. Removal began with wear on the top part of the acrylic component, followed by displacement of the acrylic component with a sharp tipped instrument, and when it was loose, the resin was removed with clinical forceps. Now without the acrylic component, the appliance was kept in place for a further 6 months, until there was bone formation in the separated area (Fig. 4).
6.
Discussion
The purpose of the present article was to describe a new option to use in the rapid maxillary expansion procedure. The goal of the described appliance is to present the favorable characteristics of the Haas and Hyrax appliances. The Haas type of appliance has an acrylic resin component that helps during separation, by providing mucosal and dental support, resulting in more anchorage and reducing the effects on the teeth. Whereas this acrylic component helps separation in the initial phases, it leads to food and bacteria accumulation in the containment phase. In an endeavor to make the Haas appliance more hygienic, Biederman developed the Hyrax appliance that has the same
38
orthodontic waves 69 (2010) 33–38
indications as those of the Haas unit, however, with support only on the teeth, without the acrylic component. If, on the one hand, removal of the acrylic made it more hygienic, on the other, it reduced anchorage, providing a greater effect on the teeth during the attempt to open the suture, particularly in patients at an advanced age. In the search for a compromise between the two, it was decided to place the acrylic component in the initial stage of activation, and remove it in the containment stage. The metal structure of the appliance is similar to that of the Hyrax appliance, but the acrylic component has been added to it. The acrylic is inserted in such a way that its postactivation removal is facilitated. A smaller quantity of acrylic was placed, making it easy to remove without compromising anchorage. After having achieved the desired separation, the screw was stabilized with a braided ligature wire, and this method was chosen because it is hygienic and it is easy for the patient to clean. In the same stabilization session, the acrylic component was removed. The removal procedure was performed by weakening the top surface of the acrylic block with a high speed bur for resin removal, and once weakened, it was easy to remove. With the treatment performed in this clinical case, the appliance here described demonstrated its effectiveness when compared with the Haas separator. The disadvantage with regard to the use of this new separator arises from the need to add a clinical stage, which would be to remove the acrylic. The stage is unnecessary when separators of the Hass and Hyrax types are used.
7.
Conclusion
The described appliance was shown to be effective for palatine suture separation, and more hygienic in the containment stage, preventing the accumulation of microorganisms and biofilm formation.
references
[1] Boryor A, Geiger M, Hohmann A, Wunderlich A, Sander C, Martin Sander F, et al. Stress distribution and displacement analysis during an intermaxillary disjunction—a threedimensional FEM study of a human skull. J Biomech 2008;41:376–82. [2] Gordon JM, Rosenblatt M, Witmans M, Carey JP, Heo G, Major PW, et al. Rapid palatal expansion effects on nasal airway dimensions as measured by acoustic rhinometry. Angle Orthod 2009;79:1000–7. [3] Kilic N, Oktay H. Effects of rapid maxillary expansion on nasal breathing and some naso-respiratory and breathing problems in growing children: a literature review. Int J Pediatr Otorhinolaryngol 2008;72:1595–601. [4] Hayes JL. Rapid maxillary expansion. Am J Orthod Dentofacial Orthop 2006;130:432–3 [author reply 433–434]. [5] De Coster T. Orthopedic expansion of the maxilla. Orthod Fr 2006;77:253–64. [6] Arman A, Ufuk Toygar T, Abuhijleh E. Evaluation of maxillary protraction and fixed appliance therapy in Class III patients. Eur J Orthod 2006;28:383–92. [7] Buccheri A, Dilella G, Stella R. Rapid palatal expansion and pharyngeal space. Cephalometric evaluation. Prog Orthod 2004;5:160–71. [8] Chung CH, Font B. Skeletal and dental changes in the sagittal, vertical, and transverse dimensions after rapid palatal expansion. Am J Orthod Dentofacial Orthop 2004;126:569–75. [9] Ren Y. Rapid maxillary expansion treatment could produce long-term dental arch changes. Evid Based Dent 2005;6:93–4. [10] Haas AJ. Rapid Expansion of the maxillary dental arch and nasal cavity by opening the mid-palatal suture. Angle Orthod 1961;31:73–90. [11] Goldenberg DC, Goldenberg FC, Alonso N, Gebrin ES, Amaral TS, Scanavini MA, et al. Hyrax appliance opening and pattern of skeletal maxillary expansion after surgically assisted rapid palatal expansion: a computed tomography evaluation. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2008. [12] Biederman WA. A hygienic appliance for rapid expansion. J Pract Orthod 1968;2:67–70. [13] Erverdi N, Sabri A, Kucukkeles N. Cephalometric evaluation of Haas and Hyrax rapid maxillary appliances in the treatment of the skeletal maxillary transverse deficiency. J Marmara Univ Dent Fac 1993;1:361–6.
available at www.sciencedirect.com
journal homepage: www.elsevier.com/locate/odw
Short communication
Mixed separator appliance: A new option for maxillary expansion Matheus Melo Pithon * Faculty of Dentistry, Federal University of Rio de Janeiro – UFRJ, Brazil
article info
abstract
Article history:
The aim of this article was to describe the fabrication and clinical application of a new
Received 16 September 2009
separator appliance that allies the favorable characteristics of the Haas and Hyrax types of
Received in revised form
separators. With this appliance separation of the median palatine suture was achieved with
4 November 2009
greater support with the acrylic component in the active period and better hygiene without
Accepted 10 November 2009
the acrylic component in the period of containment. Therefore it could be concluded that
Published on line 9 December 2009
the mixed separator appliance is a good option for performing rapid maxillary expansion. # 2009 Elsevier Ltd and the Japanese Orthodontic Society. All rights reserved.
Keywords: Rapid maxillary expansion Maxillary expansion
1.
Introduction
One of the most recognized clinical procedures in orthodontic practice, due to its efficiency and predictability, is rapid maxillary expansion (RME) [1]. RME or separation corrects the transverse atresia of the maxilla, an extremely frequent type of malocclusion that is established early and is not selfcorrecting [2]. The literature mentions an infinite number of appliances used for this purpose [3–9], nevertheless, the most used and disseminated appliances up to today are the appliances of the Haas [10] and Hyrax type [11,12]. The Haas separator appliance idealized by this author in 1961 [10] is composed of orthodontic bands fabricated for the first molar and first premolar on each side, which are united by a structure made of stainless steel wire by the vestibular and palatine ends of the bands, and a central screw. All these elements are incorporated into an acrylic mass that stays in contact with the palatine mucosa. The Haas appliance uses a dento-mucosal supported anchorage system. The magnitude
of force released by this appliance, associated with its anchorage system, provide excellent orthopedic movement (movement of the bone bas) with minimal orthodontic movement response (tooth movement). However, when this appliance is removed, thick biofilm accumulation is noted under the acrylic component. In an endeavor to make the separator more hygienic, Biederman [11,12] developed the Hyrax appliance which, in the same way as the Haas appliance is fabricated with bands on the first molars and first premolars, which are united by the vestibular and palatine faces, by means of a stainless steel wire and an expansion screw that has four cast steel wire rods, and each of these rods is welded to the four bands of the molars and premolars. It is differentiated from the Haas by the anchorage, which in this model anchorage is purely dental. It presents a certain amount of orthodontic movement (tooth movement), in addition to orthopedic movement (bone movement), which would be its limitation [13].
* Correspondence address: At Av. Ota´vio Santos, 395, sala 705, Centro Odontome´dico Dr. Altamirando da Costa Lima, Vito´ria da Conquista, CEP: 45020-750, Bahia, Brazil. Tel.: +55 7730842020. E-mail address: [email protected]. 1344-0241/$ – see front matter # 2009 Elsevier Ltd and the Japanese Orthodontic Society. All rights reserved. doi:10.1016/j.odw.2009.11.001
34
orthodontic waves 69 (2010) 33–38
In an endeavor to reduce the limitations of these two appliances, the aim of the present article was to describe the fabrication of a new separator appliance that allies the favorable characteristics of the Haas and Hyrax types of separators.
2.
Case report
The patient with 13-year-old leukoderma boy, came to the orthodontic consulting rooms with the chief complaint of
crooked teeth. In the intraoral clinical exam, maxillary atresia was noted, with lack of space for eruption of the maxillary left canine (23) (Fig. 1). As complementary exams, periapical, panoramic, teleradiographic and superior occlusal radiographs of the maxilla were requested (Fig. 1f). From the preceding evaluations, the option was to perform orthopedic– orthodontic treatment, beginning with the placement of a maxillary suture separating orthodontic appliance, followed by correcting the position of the teeth by means of a fixed orthodontic appliance.
Fig. 1 – (a–e) Initial intraoral photographs and (f) initial occlusal radiograph.
orthodontic waves 69 (2010) 33–38
35
Fig. 2 – (a) Screw adaptation, (b) welding the screw to the orthodontic bands, (c) isolation of the screw orifices and making the dyke with radiographic film, (d) concluded appliance and (e) intraoral photographs after placement of the separator.
3.
Description of the separator appliance used
The appliance was fabricated on bands adapted to the maxillary first premolars (14 and 24) and maxillary first molars (16 and 26). Once the transfer model with the bands in place was obtained, an expansion screw with long rods was contoured. After contouring, the rods were welded to the bands, and the weld was polished.
After this, the screw was covered with wax to prevent the resin from obliterating the orifices for the purpose of activating it during acrylization. In order to separate the acrylic components of the left and right sides, a piece of used radiographic film served as a dyke, and was placed exactly over the median palatine suture. After the preparatory stage, the acrylic component was applied by the powder/liquid technique. Once it was polymerized, it was finished and polished (Fig. 2).
36
orthodontic waves 69 (2010) 33–38
Fig. 3 – (a–d) Intraoral photographs at the end of 21 of activation and (e) occlusal radiograph after separation.
4.
Activation of the appliance
After cementation (Fig. 2e), a period of 30 min was waited before performing the first activations. Initially it
was activated 4 (1 mm), and the patient was instructed to activate it 2 a day for 7 days, and then return to the consulting room. At the end of 21 days of activation, the necessary separation of 11.5 mm was obtained (Fig. 3).
orthodontic waves 69 (2010) 33–38
37
Fig. 4 – (a) Acrylic surface wear, (b) acrylic displacement with the sharp pointed instrument; (c) acrylic removal with forceps, (d) polishing the metal structure, (e) appliance after removal of the acrylic component and (f) acrylic component removed.
5. Stabilization and removal of the acrylic component After obtaining the desired separation, the screw was stabilized with a braided ligature wire. In the same session, the acrylic component was removed with the aid of a bur for resin removal mounted in a high speed handpiece. Removal began with wear on the top part of the acrylic component, followed by displacement of the acrylic component with a sharp tipped instrument, and when it was loose, the resin was removed with clinical forceps. Now without the acrylic component, the appliance was kept in place for a further 6 months, until there was bone formation in the separated area (Fig. 4).
6.
Discussion
The purpose of the present article was to describe a new option to use in the rapid maxillary expansion procedure. The goal of the described appliance is to present the favorable characteristics of the Haas and Hyrax appliances. The Haas type of appliance has an acrylic resin component that helps during separation, by providing mucosal and dental support, resulting in more anchorage and reducing the effects on the teeth. Whereas this acrylic component helps separation in the initial phases, it leads to food and bacteria accumulation in the containment phase. In an endeavor to make the Haas appliance more hygienic, Biederman developed the Hyrax appliance that has the same
38
orthodontic waves 69 (2010) 33–38
indications as those of the Haas unit, however, with support only on the teeth, without the acrylic component. If, on the one hand, removal of the acrylic made it more hygienic, on the other, it reduced anchorage, providing a greater effect on the teeth during the attempt to open the suture, particularly in patients at an advanced age. In the search for a compromise between the two, it was decided to place the acrylic component in the initial stage of activation, and remove it in the containment stage. The metal structure of the appliance is similar to that of the Hyrax appliance, but the acrylic component has been added to it. The acrylic is inserted in such a way that its postactivation removal is facilitated. A smaller quantity of acrylic was placed, making it easy to remove without compromising anchorage. After having achieved the desired separation, the screw was stabilized with a braided ligature wire, and this method was chosen because it is hygienic and it is easy for the patient to clean. In the same stabilization session, the acrylic component was removed. The removal procedure was performed by weakening the top surface of the acrylic block with a high speed bur for resin removal, and once weakened, it was easy to remove. With the treatment performed in this clinical case, the appliance here described demonstrated its effectiveness when compared with the Haas separator. The disadvantage with regard to the use of this new separator arises from the need to add a clinical stage, which would be to remove the acrylic. The stage is unnecessary when separators of the Hass and Hyrax types are used.
7.
Conclusion
The described appliance was shown to be effective for palatine suture separation, and more hygienic in the containment stage, preventing the accumulation of microorganisms and biofilm formation.
references
[1] Boryor A, Geiger M, Hohmann A, Wunderlich A, Sander C, Martin Sander F, et al. Stress distribution and displacement analysis during an intermaxillary disjunction—a threedimensional FEM study of a human skull. J Biomech 2008;41:376–82. [2] Gordon JM, Rosenblatt M, Witmans M, Carey JP, Heo G, Major PW, et al. Rapid palatal expansion effects on nasal airway dimensions as measured by acoustic rhinometry. Angle Orthod 2009;79:1000–7. [3] Kilic N, Oktay H. Effects of rapid maxillary expansion on nasal breathing and some naso-respiratory and breathing problems in growing children: a literature review. Int J Pediatr Otorhinolaryngol 2008;72:1595–601. [4] Hayes JL. Rapid maxillary expansion. Am J Orthod Dentofacial Orthop 2006;130:432–3 [author reply 433–434]. [5] De Coster T. Orthopedic expansion of the maxilla. Orthod Fr 2006;77:253–64. [6] Arman A, Ufuk Toygar T, Abuhijleh E. Evaluation of maxillary protraction and fixed appliance therapy in Class III patients. Eur J Orthod 2006;28:383–92. [7] Buccheri A, Dilella G, Stella R. Rapid palatal expansion and pharyngeal space. Cephalometric evaluation. Prog Orthod 2004;5:160–71. [8] Chung CH, Font B. Skeletal and dental changes in the sagittal, vertical, and transverse dimensions after rapid palatal expansion. Am J Orthod Dentofacial Orthop 2004;126:569–75. [9] Ren Y. Rapid maxillary expansion treatment could produce long-term dental arch changes. Evid Based Dent 2005;6:93–4. [10] Haas AJ. Rapid Expansion of the maxillary dental arch and nasal cavity by opening the mid-palatal suture. Angle Orthod 1961;31:73–90. [11] Goldenberg DC, Goldenberg FC, Alonso N, Gebrin ES, Amaral TS, Scanavini MA, et al. Hyrax appliance opening and pattern of skeletal maxillary expansion after surgically assisted rapid palatal expansion: a computed tomography evaluation. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2008. [12] Biederman WA. A hygienic appliance for rapid expansion. J Pract Orthod 1968;2:67–70. [13] Erverdi N, Sabri A, Kucukkeles N. Cephalometric evaluation of Haas and Hyrax rapid maxillary appliances in the treatment of the skeletal maxillary transverse deficiency. J Marmara Univ Dent Fac 1993;1:361–6.